Friction shock-absorbing mechanism



J. F. OCONNOR.

FRICTION SHOCK ABSORBINVG MECHANISM.

APPLICATION FILED 0CT.4. 1920.

PatentedSept. 20, 1921.

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UNITED STATES PATENT OFFICE.

JOHN F. O'CONNOR, OF CHICAGO, ILLINOIS, ASSIGNOR TO WILLIAM H. MINER, OF

CHAZY, NEW YORK.

FRICTION SHOCK-ABSORBING MECHANISM.

Specification of Letters Patent.

Patented Sept. 20, 1921.

Application filed October 4, 1920. Serial No. 414,666.

To all whom it may concern:

Be it known that I, JOHN F. OCoNNoR, a citizen of the United States, residing at Chi cago, in the county of Cook and Statefof lllinois, have invented a certain new and useful Improvement in FrictionShoclz-AbsorbingMechanisms, of which the followmg is a full, clear, concise, and exact description, reference being had to the accompany ing drawings, forming a part of this specification.

This invention relates to improvements in friction shock absorbing mechanism.

One object of the invention is to provide a high capacity friction shock absorbing mechanism especially adapted for railway draft riggings and more especially such a mechanism wherein the release or restoring effectof the spring resistance is temporarily multiplied to several times that of the actual capacity of the spring, during the initial release action of the friction parts.

Other objects of the invention will more clearly appear from the description hereinafter following.

In the drawing forming a part of thisspecification, Figure 1 1s a horizontal, longi-' tudinal, sectional view of a portion of a railway draft rigging showing my improvements in connection therewith. Fig. 2 is a vertical, transverse, sectional view corresponding substantially to the line 2-2 of 1. Fig. 3 is a sectional view corresponding to Fig 1 showing the outer or front portion of the shock absorbing mechanism proper with the 1 parts in the position sumed at the end of the compressive stroke. And Figs. 4 and. 5 are detail perspectivesof one of the wedge elements and one of the levers, respectively, employed in my construction.

in said drawing, 10-10.denote channel center or draft sills of a railway car, to the inner faces of which are secured front'stop lugs 11 and rear stop lugs 12 of well known form. The rear portion of a drawbar is indicated at 13, the same being connected to a hooded cast steel yoke 14 by means of a conpler key 15. The shock absorbing mecha- .zism proper is disposed within the yoke as ls also a front follower 16. The yolre and associated movable parts are supported by a detachable saddle plate 17.

The improved shock absorbing mechanism gn'oper, as shown, comprises, broadly, a combined friction shell and spring cage casting A; a spring resistance B; a pair of friction shoes CC; a pressure-transmittin Wedge block D; a pair of Wedge elements E; a pair of levers F-F a spring cap or follower G; and a retainer bolt H.

In carrying-out my invention, the casting A is preferably formed with a friction shell or barrel 18 at the forward end thereof, said shell, in the instance shown, being of rectangular formation having upper and lower walls 19-19 and side walls 20-20, the latter having interior longitudinally extending friction surfaces 21-21. The spring cage 22 is formed at the rear end of the casting A. and is preferably reduced in diameter to form a cylindrical centering casing for the spr ng B. The casting A has an integral rear wall 23 laterally extended so as to function as the rear follower of the mechanism in conjunction with the stop lugs 12.

The'spring B preferably consists of an outer heavy coil 24 and an inner lighter nested coil 25.

The retainer bolt H passes centrally through the-spring B, through alined perforations in the rear wall of the casting A, in the spring cap G, in the wedge block D and within notches 2626 formed at the inner ends of the levers F. The function of the bolt H is to maintain the parts in assembled relation and also to hold the spring under an initial compression when desired.

The two friction shoes C are of like construction and each is formed on its outer side with a flat friction surface 27 cooperable with a. corresponding opposed frict on surface 21 of the shell. On its inner side, each shoe C is formed with a wedge face 28 extending at a relatively atute angle with respect to the axis of the mechanism. In addition, each shoe C is also formed with a rounded seat or hearing 29 for the corresponding rounded fulcrum end 30 of a lever 1 The mouth of each bearing 29 is flared and on the inner side the opening is so formed as to provide a limiting shoulder or ledge 31 for the corresponding lever F in its pivotal movements relatively to the shoe as will be clear from an inspection of Fig. 3.

The levers F correspond in number to the friction shoes C and, in cross section as shown in Figs. 1 and 3-, are tapered from their fulcrum ends to their inner ends, the latter being extended substantially to a vertical line passing through the axis of the mechanism.

The wedge block D is preferably in the form of'a hollow casting and has two wedge faces 32 which converge inwardly of the shell and are arranged at'a relatively blunt angle with respect to the-axis of the mechanism.

The wedge elements E are of like construction and each is provided on its inner sidewith a wedge face 132 cooperable with a wed e face 32. On its outer side, each element is formed with another wedge face 128 cooperable with a corresponding opposed wedge. face 28 of a shoe C. At its inner end, each element E is extended inwardly beyond the shoe wedge face 28 and has a rounded bearing edge 33"a-dapted to engage a corresponding lever F.

The spring cap or follower G has'a cupshaped portion 3 L which is provided with a flat outer bearing surface 35, said cupshaped portion normally being disposed within the inner ends of the shoes C and with the corresponding fiat transversely extending faces 36 of the levers F when the latter are in their normal or full released position. In addition, the cap F isprovided with a laterally extending annular flange 37 adapted to engage the inner ends of the friction shoes when the parts are in full release, as shown in Fig. 1. The inner edges of the levers F are rounded as indirated at 38 so as to obtain a line bearing on the cap F during the operation of the mechanism, as hereinafter described.

The operation of the mechanism is as follows, assuming an inward or bufling movement of the drawbar. As the drawbar and front follower move inwardly while the shell A remains stationary, it is evident that .thewedge block D will be moved at the same rateas the follower 16. In the initial part of the compressive stroke for an almost 'shell.

the shoes, the wedge block D carries with it infinitesimal interval of time, thefriction shoes remain stationary relatively to the shell due to the inertia of the parts-and the static friction between the shoes and the As a result of. this initial inertia of and substantially all acting as a solid unit, the wedge elements E and the latter are therefore more tightly wedged within or pushed inwardly of the shoes C. As the elements E are advanced longitudinally relatively to the shoes C during the initial nonmovement of the latter, it is evident that the levers F will be oscillated or swung slightly relatively to the shoes C. The said movement of the elements E and block I) relatively to the shoes C will be sufficient to break the flat surface engagement between the levers F and the follower G, that is, will change the point of contact between the follower G to the rounded inner ends of the tinues, the resistance to the movement of the shoes C gradually increases and there will be a gradual increase of the slippage of the elements E and block D relative to the shoes until the levers F assume the position shown in Fig. No. 3, that is, with the levers F in engagement with the shoulders 31.

Upon removal of the actuating force, the following action takes place in the release: It will be noted from an inspection of Fig. 3 that the spring B bears at the inner ends of the levers F at the points most remote from the fulcrum whereas the points of engagement of the wedge elements E with the levers F are much nearer the fulcrum centers of the levers F. The effective leverage of the spring and elements E with respect to the levers is preferably made in the ratio of 3 or 4 to 1. With this construction it is apparent that the effect of the spring acting through the levers F on the wedge times in a direction to expel or kick out the elements E longitudinally. In other words, in the initial part of the release action, the releasing effect of the spring as transmitted to the wedge elements is multiplied several times with consequent advantage in assuring a certain and full release of the mechanism. The spring acting through the levers F on the elements E forces the wedge elements outwardly while the shoes initially remain stationary and until the spring cap or follower G engages with the inner ends of the shoes. Thereafter all of the parts are projected outwardly until the full release position is obtained. -During the release action it is also evident that the levers F bear on the wedge elements E in such a way as to tilt or tend to tilt the latter about their outer ends on the shoes C'with the result that the wedge block D is easily released with respect to the elements E because of the bluntangled engagement therebetween.

' Although I have herein shown and describedavhat I now consider the preferred manner of carrying out the invention, the same is merely illustrative IT-d I contemplate all changes and modifications that come within the scope of the claims appended. hereto.

I claim:

'1. In a friction shock absorbing mechanism, the combination with a friction shell; of friction shoes cooperable with the shell; a spring; a spring follower; a compound multiple-part wedge; and levers each having bearing contact with said spring follower, a shoe, and a' wedge part.

2. In a friction shock absorbing mechanism, the combination with a friction shell; of friction shoes cotiperable with the shell; a spring; a spring follower; a compound multiple-part wedge; and, levers, each lever being :tulcrumed at one end on a shoe and having bearing engagement on one side with said follower and on the opposite side thereof with a wedge part.

3. In a friction shock absorbing mechanism. the combination with a friction shell; of friction shoes cooperating with the shell; :1 spring; a spring follower; a. compound multiple-part wedge; and levers, each lever being fulcrumed at one end on a shoe and having bearing engagement on one side with said follower and on the opposite 'side thereof with a wedge part, the point of bearing contact of-the. wedge part with said lever being nearer the fulcrum than the point of bearing contact between said lever and the spring follower.

4. In a friction shock absorbing mechanism, the combination with a friction shell; of friction shoes cooperable with the shell; a wedge within and co-acting with said shoes; a spring; a spring follower; and l; \crs, corresponding in number to the shoes, each fulcrumed on a shoe and having bearing engagement with said spring follower, said wedge having also bearing engagement with the levers intermediate the fulcrums of the latter andthe points of bearing contact with the follower.

5. In a friction shock .absorbing mechanism, the combination with a friction shell; of friction shoes cooperable with the shell; a wedge within and co-acting with said shoes; a spring; a spring follower; levers, corresponding in number to the shoes, each fulcrumed on a shoe and having bearing engagement with said spring follower, said wedge having also bearing engagement with the levers intermediate the fulcrums of the latter and the points of bearing with the follower; and means for limiting the pivotal movement of said levers relatively to the shoes in a direction toward the spring.

6. In a friction shock absorbing mechanism, the combination with a friction shell; of a plurality of friction shoes within and coiiperable with said shell; a wedge cooperable with said shoes a spring; and leverage-ratio multiplying means interposed between said spring and wedge to thereby multiply the effective spring resistance to relative movement between the shoes and wedge.

7. In a friction shock absorbing mechanism, the combination with a friction shell; of friction shoes cooperable therewith; a spring; a spring follower; a blunt-angled 1 ressure-transmitting wedge block; wedge elements interposed between said wedge block and friction shoes'and cooperable with both, said elements having relatively keenangled wedging engagement with the shoes; and levers, each lever having bearing contact with said spring follower, a friction shoe and the inner end of one of said wedge elements.

8. In a friction shock absorbing mechanism, the combination with a friction shell; of friction shoes cooperable therewith; a spring; a spring follower; a blunt-angled pressure-transmitting wedge block; wedge elements 'interposed between said wedge block and friction shoes and cooperable with both, said elements having relatively keenangled wedging engagement with the shoes; and levers, each lever being fulcrumed at one end on a friction shoe and having a bearing on one side thereof with said spring follower and on its opposite side thereof with the inner end of one of said wedge elements.

9. In a friction shock absorbing mechanism, the combination with a friction shell; of friction shoes cooperable therewith; a spring; a spring follower; a blunt-angled pressure-transmitting wedge block; wedge elements interposed between said wedge block and friction shoes and cooperable with both, said elements having relatively keenangled wedging engagement with the shoes; and levers, each lever being fulcrumed at one end on a friction shoe and having a bearing on one side thereof with said spring follower and on its opposite side thereof with the inner end of one of said wedge elements, the point of bearing contact of said wedge element with the lever being nearer the fulcrum than the point of bearing contact bei tween the lever and spring follower.

10. In a friction shock absorbing mechanism, the combination with a casting having a friction shell at one end thereof and a spring cage at the opposite end; of a spring disposed within said spring cage; a plurality of friction shoes within and cooperable with said shell; a spring follower interposed between said shoes and the adjacent end of the spring and normally having hearing contact with the inner end of the shoes; ablunt-angled pressure-transmitting wedge block; a plurality of wedge elements interposed between said block and the shoes and corresponding in number to the latter, said elements and the shoes having relatively keen-angled wedging engagement; and a plurality of levers corresponding in number to the shoes, each lever being fulcrumed at its outer end on a shoe and normally having flat bearing contact with said spring follower on its inner side, said wedge elements having bearing contact with said levers at points relatively near the fulcrums of the latter, said levers being oscillatable relatively to the shoes for a limited amount.

In witness that I claim the foregoing I have hereunto subscribed my name this 30th day of Sept. 1920.

JOHN F. OCONNOR.

Witness META SCHMIDT. 

